Adding and calculating machine



June 10, 1941. s. CARLSTROM ADDING AND CALCUIQATING MACHINE Original Filed July 12, 1938 2 Sheets-Sheet 1 Patented June 10, 1941 ADDING AND CALCULATING MACHINE Bengt Carlstriim, Atvldaberg, Sweden, assignor to Aktiebolaget Facit, Atvidaberg, Sweden, a corporation of Sweden Original application July 12, 1938, Serial No.

Divided and this application February 1, 1939, Serial No. 254,011. In Germany August 8, 1937 2 Claims.

This application is a division of my oopending application Serial No. 218,788, filed on July 12,

In adding and other calculating machines having a tens transfer mechanism for all wheels or pinions of one or more totalizers or registers, such as a result register, a quotient register, etc., often a special tens transfer rotor is used which carries the tens transfer teeth. When the registers have a great capacity, that is, have many denominational wheels, such rotors will get excessively bi'g dimensions, which makes the calculating machine clumsy and difiicult to handle. Due to the heavy rotary masses, such machines work slowly and run heavily. For this reason, only a partial tens transfer was often used in big registers, there being no tens transfer for the highest denominations.

It was also proposed to divide the tens transfer rotor for a register into two parts and to couple said two parts together temporarily. In that embodiment the additional tens transfer rotor for the higher denominations outside of the operation range of the actuator begins its motion later than the principal tens transfer rotor and consequently remains stationary during the first portion of the motion of the principal rotor and is then suddenly rapidly accelerated, when it is coupled to the principal rotor, which is directly driven from a main shaft. In my copending United States patent application Serial No. 218,- 788, filed on July 12, 1938, for Improvements in adding and calculating machines and the like," I have shown and claimed a tens transfer mechanism with two tens transfer rotors which are coupled together permanently for motion in unison, one of said rotors having a higher velocity than the other.

The chief object of this invention is to create a smoothly and safely working overthrow preventing mechanism for registers and totalizers of high capacity.

Another object of this invention is to create a simple and nonexpensive overthrow preventing mechanism, which is very reliable in operation and resistive to rough handling and may be operated also at high speeds.

Another object of this invention is to create an overthrow preventing mechanism, in which each locking or overthrow preventing pawl is operated by that toothed wheel, which is to be prevented from overthrow by said pawl.

Another object of this invention is to keep the locking or overthrow preventing pawls of the mechanism normally out of engagement with the toothed wheels which are to be prevented from overthrowing, and are brought into e a ent with said toothed wheels during the tens transfer.

Another object of this invention is to construct an overthrow preventing mechanism with onepiece pawls serving for both directions of rotation.

Other objects of this invention will be evident from the following specification and claims.

One embodiment of this invention is shown in the annexed drawings.

Fig. 1 shows a plan view of a calculating machine having a mechanism in accordance with this invention.

Figs. 2 and 3 show vertical sections on the lines IIII and I II--III, respectively, in Fig. 1.

Fig. 4 is a. front view of a detail.

For the sake of clearness only the essential parts of the machine are shown. The anchor pawl shown in Fig. 3 is omitted from Figs. 1, and 4 for the same reason.

The calculating machine as shown is constructed substantially in accordance with United States Patent No. 2,108,596 and has an actuator in the shape of a pin wheel rotor which is set, preferably by means of keys. In contrast to the machine shown in the said patent, the machine shown in the annexed drawings has its registers (result register and quotient register) in a displaceable carriage, as well known in the art.

Referring now to the drawings, I indicates the stationary machine frame, in which the main driving shaft 2 is rotatably journalled. Said shaft carries the actuator or pin wheel rotor 3 and may be rotated in well-known manner, for instance, by means of a manually operated crank 4. Of course, a motor may be provided instead of the crank. The rotor 3 may be tabulated to different positions along the shaft 2, for instance, in dependence on the number of numerals of the item set in said actuator. Such tabulations may be effected as described in United States Patents Nos. 2,108,596 and 2,105,520 or in United States patent application Serial No. 756,823, flied on December 10, 1934, for Improvements in calculating machines."

The extreme right position of the actuator 3 is shown in full lines in Fig. l and its extreme left position is indicated by the dash-and-dot line A. In a carriage B movable in parallel with the shaft 2 shafts 5, .6 are secured, which in the conventional manner carry register wheels or pinions I and intermediate pinions 8. In this carriage B also a shaft 9 is secured carrying tens transfer levers I (which may be constructed in accordance with Swedish Patent No, 90,- 932). Through holes in the tens transfer levers III a shaft II passes, which is secured in the carriage B and carries intermediate or transmission wheels I2 which are actuated by the settable teeth or pins I3 of the rotor 3 at the calculating operations.

In Fig. 1 the carriage B and the register 1 are shown in their extreme left position.

in the machine frame I a shaft I4 is rotatably journalled which is driven by the shaft 2 via spur gears I5. The shaft I4 carries a principal tens transfer rotor I6 which is secured to the shaft I4 and rotates together with the same. The spur wheel gears are so chosen that the shafts 2, I4 and the rotors 3, I6 effect the same number of revolutions and always have the same rotary speed. On a sleeve Ila an additional or auxiliary tens transfer rotor I1 is arranged and the sleeve I'Ia together with the rotor I1 is loosely journalled on the shaft I4 and may rotate in relation to said shaft. Via a spur gear I8 the shaft I4 drives an intermediate shaft 19 which in its turn drives the rotor I1 via a spur wheel gear 20. In the embodiment shown the additional rotor I1 is driven twice as many revolutions as those of the main rotor I6, but the ratio of transmission between said two rotors may be chosen arbitrarily, in dependence on the fact, in how many positions tens transfer is desired. But said ratio of transmission must always be so chosen that the additional rotor Ii effects an integral number of revolutions, but at least two revolution-s, for each revolution of the principal rotor I6.

The two rotors or cylinders I6, I? are provided with rockable tens transfer teeth 2I, 22 in the conventional manner. Those teeth are arranged along helical lines on the rotors. The extreme left transfer pin 2I (that is the tens transfer pin of the highest denomination) of the rotor I6 and the extreme right transfer pin 22 (that is the tens transfer pin of the lowermost denomination) of the rotor I1 are arranged in such angular posi tions, with regard to the different rotary velocities of the rotors that when said highest denominational transfer pin 2| passes by the oblique cam or projection 23 of the corresponding tens transfer lever ID the lowermost denominational transfer lever 22 is in correct position for carrying the tens transfer further to the higher denominations of the register. In other words: in that moment in which the highest transfer pin 2| passes by the corresponding cam 23, the pins 2| and 22 form a continuous helical line for that direction of rotation. Consequently, the two rotors act as one single rotor having a continuous helical line of transfer pins for the direction of rotation concerned, a tens transfer being thus effected throughout the whole register.

On a stationary shaft 24 a bridge 25 is rockable, which carries locking pawls 26, one for each denomination of the register to the left of the extreme left hand position A of the actuator 3. These pawls are rotatable on the shaft 21, which is secured in the bridge 25. The pawls are separately loaded by springs 28 and each pawl 26 has two narrower teeth 26a and two broader outer teeth or projections 26b. The bridge 25 car ries a roller 29, which is rotatable on the shaft 21 and engages a cam disc 30 on the shaft 2. A

spring 3| presses the roller 30 to engage the cam disc permanently. The tens transfer tooth of the wheel I2 is indicated by 32 and engages the pin 33 of the lever III at the tens transfer operation.

The device described operates as follows:

When at a tens transfer .to one denomination of the register, the tens transfer tooth 32 of the wheel I2 of the next lower denomination engages the pin 33 of the lever I0, said lever is rocked counter-clockwise from its position of rest shown in Figs. 2 and 3. The wedge-shaped projection 23 (Fig. 4) of the lever It! then enters the path of the corresponding transfer pin 2| (or 22) of the tens transfer rotor I6 (or II) and rocks said pin laterally, that is, in the axial direction, so much that the latter engages the intermediate wheel I2 of the next higher denomination and rotates the latter together with the wheels 8 and I of this next higher denomination one step, thus completing the tens transfer. At the beginning of the rotation of the shaft 2 the bridge 25 is rocked inwards towards the wheels I2 by the cam disc 30, causing the pawls 26 to engage those of said wheels, which are to the left of the position A of the actuator 3. It is to be observed that the pawls 26 are normally held by the springs 28 in the middle position shown in Fig. 3 and are out of engagement with the wheels I2. But as soon as the shaft 2 is rotated (for a calculating operation) the bridge 25 is rocked by the cam disc 30 and the pawls 26 are brought into engagement with the wheels I2. If now a tens transfer is effected in a denominational position whose wheels are engaged by the pawls 26, the wheel I2 is rocked one step as described above and rocks the pawl 26 in the corresponding direction so that one of the narrow teeth 26a enters the space between the teeth. Further rotation of the pawl 26 and the wheel I2 is then positively prevented by the fact that the corresponding outer tooth 26b is so broad that it cannot enter a space between the teeth of the wheel I2 but instead locks the wheel I2 and prevents an overthrow. At the continued rotation of the shaft 2 the roller 29 follows the periphery of the cam disc 30 and consequently holds the pawl 26 against the wheels I2 during the whole period in which the tens transfer is effected, because that part of the cam disc is cylindric (non-eccentric) Thus an efllcient locking of the wheels I2 is effected and errors of calculation are prevented. When the tens transfer has been completed, the roller 29 again slides down upon the lower part of the cam disc 30, causing the pawls 26 to be drawn out of engagement with the wheels I2 and to be restored by their springs 28 to their positions of rest as shown in Fig. 3.

It is to be observed that the springs 28 of the individual pawls 26 need only be weak, because they only serve the purpose of returning the pawls 26 to their normal or middle position, when the pawls 26 have been disengaged from the wheels I2. After the tens transfer has been completed said springs 28 cannot rotate the wheels I2 back again, because the wheels I2 are held in position by the ordinary strong springs of their anchor pawls (lever escapement pawls). (These pawls are shown at 2 in Swedish Patent No. 90,932.)

Stress is laid upon the fact that the operation of the mechanism is the same for both directions of rotation, that is both for addition and subtraction, or multiplication and division.

Obviously, the device may also be used for nondecimal calculating machines. such as calculating machines ior English coinage (duodecimal and vigesimal system). Because the actuator hasno influence upon the tens transfer mechanism, the device in accordance with this invention may obviously be applied to calculating machines oi othertypesthanthatahowninthedrawings.

Whilelhave disclosedone moreorlessspeciilc embodiment oi my invention, it is to be understoodthatthishasbeendoneiorthem l oi illustration only, and that the scope oi my inventionisnottohe llmitedtlmreto, but istohe determined by the appended claims. Moreover. certain subject matter herein disclosed but not claimed is claimed in my copending application Serial No. 218,788.

What I claim is:

1. In a calculating machine having a register wheel. a locking pawl ior said wheel having one tther gisterwheeltomoyeonesingle s andthento stop the wheel positively, and means ior rocking said pawl about a ilrst axis into and out oi engagement with said wheel, said pawl being mounted for pivotal movement about a second axis aiter engagement with said wheel.

2. In a calculating machine having a register wheel, a locking pawl for said wheel having two broad teeth and between them an narrow teeth. and means for rocking said pawl about a first axis into and out oi engagement with said wheel. said pawl being mounted for piyotal movement about a second axis siter engagement with said wheel.

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